1. Field of the Invention
The present invention relates to an image recording apparatus and a method in which a photosensitive material is exposed to form an image thereon.
2. Description of the Related Art
In recent years, digital photoprinters have been practically utilized as printing apparatus that utilize digital exposure. In a printing apparatus, initially, an image recorded on a film is photoelectrically read and the read image is converted to a digital signal. Thereafter, the image that has been converted to the digital signal is subjected to various image processing, whereby image data for recording is generated. A photosensitive material is then scan-exposed with recording light modulated in accordance with the image data to record the image (latent image) on the photosensitive material. Finally, the photosensitive material is developed and processed, and outputted as a print (photograph).
In a digital photoprinter, an image recorded on a film is photoelectrically read and gradation correction is carried out by processing the read image (i.e., the digital signal) to determine exposure conditions. Therefore, editing of a print image, such as synthesizing many images or dividing images, and various types of image processing, including color/density adjustment and edge enhancement, can be performed freely. Namely, a print that has been image-processed freely in accordance with the application to which it to be put can be outputted. Image data for print images can also be supplied to a computer or the equivalent, and stored in a recording medium such as a floppy disk. Moreover, the digital photoprinter can output prints having better resolution, color/density reproducibility and image quality than conventional prints which are directly exposed.
The digital photoprinter basically comprises an input unit, which includes a scanner (image reading apparatus) and an image processing apparatus, and an output unit, which includes a printing apparatus (image recording apparatus) and a developing apparatus. In the scanner, light transmitted through an image recorded on a film is photoelectrically read by an image sensor such as a CCD sensor, and transmitted to the image processing apparatus as image data (image data signal) for the film. In the image processing apparatus, the image data is subjected to predetermined image processing, and the processed image data is transmitted to the printing apparatus as output image data (exposure conditions) for image recording. When the printing apparatus uses light beam scan-exposure, a light beam which has been modulated in accordance with the supplied image data is deflected in a main scanning direction, and a photosensitive material is scan-conveyed in a sub-scanning direction orthogonal to the main scanning direction. In this manner, the photosensitive material is scan-exposed with the light beam to form a latent image, and a back print is recorded. In the developing apparatus, the exposed photosensitive material is subjected to predetermined development and processed, whereby a print on which the image recorded on the film has been reproduced is formed.
Image formation is continuously repeated in this manner by main-scanning with a light beam the elongated photosensitive material, which is wound in a roll, while conveying the photosensitive material in the sub-scanning direction. The photosensitive material is then developed and cut into a predetermined length to make a print.
In the image recording apparatus of the digital photoprinter, a pair of conveyance rollers is disposed both upstream and downstream (i.e., in the direction that the photosensitive material is conveyed) from a position at which the photosensitive material is exposed (hereinafter, may be referred to as exposure position). The photosensitive material nipped between the conveyance rollers during exposure to ensure that the photosensitive material is flat, so that an image can be accurately formed on the photosensitive material.
In this case, because the two pairs of conveyance rollers do not move into a position at which to nip the photosensitive material until a leading edge of the photosensitive material has passed through the downstream pair of conveyance rollers and the photosensitive material has reached a position at which exposure can be conducted, misregistration of the photosensitive material due to impact of the photosensitive material against conveyance rollers already predisposed in a nipping position is prevented. After the leading edge of the photosensitive material has passed through the downstream pair of conveyance rollers, the two pairs of conveyance rollers nip the photosensitive material as the photosensitive material is exposed, whereby the photosensitive material is nipped at a predetermined position to accurately form an image on the photosensitive material.
However, since the lengthy photosensitive material which is wound in a roll, the photosensitive material tends to curl in the conveyance direction. Therefore, the photosensitive material can become jammed at the exposure position when the leading edge of the photosensitive material passes through the upstream pair of conveyance rollers and proceeds between the pair of downstream conveyance rollers.
Namely, in the conventional image recording apparatus, there is a drawback that an image cannot be accurately formed on the photosensitive material.